/**
   * Attempts to prepare the request for a retry. If there are no more attempts remaining in the
   * request's retry policy, a timeout exception is thrown.
   *
   * @param request The request to use.
   */
  private static void attemptRetryOnException(
      String logPrefix, Request<?> request, VolleyError exception) throws VolleyError {
    RetryPolicy retryPolicy = request.getRetryPolicy();
    int oldTimeout = request.getTimeoutMs();

    try {
      retryPolicy.retry(exception);
    } catch (VolleyError e) {
      request.addMarker(String.format("%s-timeout-giveup [timeout=%s]", logPrefix, oldTimeout));
      throw e;
    }
    request.addMarker(String.format("%s-retry [timeout=%s]", logPrefix, oldTimeout));
  }
 /** Logs requests that took over SLOW_REQUEST_THRESHOLD_MS to complete. */
 private void logSlowRequests(
     long requestLifetime, Request<?> request, byte[] responseContents, StatusLine statusLine) {
   if (DEBUG || requestLifetime > SLOW_REQUEST_THRESHOLD_MS) {
     VolleyLog.d(
         "HTTP response for request=<%s> [lifetime=%d], [size=%s], " + "[rc=%d], [retryCount=%s]",
         request,
         requestLifetime,
         responseContents != null ? responseContents.length : "null",
         statusLine.getStatusCode(),
         request.getRetryPolicy().getCurrentRetryCount());
   }
 }
  @Override
  public NetworkResponse performRequest(Request<?> request) throws VolleyError {
    long requestStart = SystemClock.elapsedRealtime();
    while (true) {
      HttpResponse httpResponse = null;
      byte[] responseContents = null;
      Map<String, String> responseHeaders = new HashMap<String, String>();
      try {
        // Gather headers.
        Map<String, String> headers = new HashMap<String, String>();
        addCacheHeaders(headers, request.getCacheEntry());
        String url = request.getUrl();

        VolleyLog.e("performRequest parsedUrl %s ", url);

        HashMap<String, String> map = new HashMap<String, String>();
        map.putAll(request.getHeaders());
        map.putAll(headers);

        for (String headerName : map.keySet()) {
          VolleyLog.e(
              "performRequest headerName %s headerValue %s", headerName, map.get(headerName));
        }

        httpResponse = mHttpStack.performRequest(request, headers);
        StatusLine statusLine = httpResponse.getStatusLine();
        int statusCode = statusLine.getStatusCode();

        responseHeaders = convertHeaders(httpResponse.getAllHeaders());
        // Handle cache validation.
        if (statusCode == HttpStatus.SC_NOT_MODIFIED) {
          return new NetworkResponse(
              HttpStatus.SC_NOT_MODIFIED,
              request.getCacheEntry() == null ? null : request.getCacheEntry().data,
              responseHeaders,
              true);
        }

        // Some responses such as 204s do not have content.  We must check.
        if (httpResponse.getEntity() != null) {
          responseContents = entityToBytes(httpResponse.getEntity());
        } else {
          // Add 0 byte response as a way of honestly representing a
          // no-content request.
          responseContents = new byte[0];
        }

        // if the request is slow, log it.
        long requestLifetime = SystemClock.elapsedRealtime() - requestStart;
        logSlowRequests(requestLifetime, request, responseContents, statusLine);
        VolleyLog.e("response code %d for %s", statusCode, request.getUrl());
        if (statusCode < 200 || statusCode > 299) {
          throw new IOException();
        }
        return new NetworkResponse(statusCode, responseContents, responseHeaders, false);
      } catch (SocketTimeoutException e) {
        attemptRetryOnException("socket", request, new TimeoutError());
      } catch (ConnectTimeoutException e) {
        attemptRetryOnException("connection", request, new TimeoutError());
      } catch (MalformedURLException e) {
        throw new RuntimeException("Bad URL " + request.getUrl(), e);
      } catch (IOException e) {
        e.printStackTrace();
        int statusCode = 0;
        NetworkResponse networkResponse = null;
        if (httpResponse != null) {
          statusCode = httpResponse.getStatusLine().getStatusCode();
        } else {
          throw new NoConnectionError(e);
        }
        VolleyLog.e("Unexpected response code %d for %s", statusCode, request.getUrl());
        if (responseContents != null) {
          networkResponse =
              new NetworkResponse(statusCode, responseContents, responseHeaders, false);
          if (statusCode == HttpStatus.SC_UNAUTHORIZED || statusCode == HttpStatus.SC_FORBIDDEN) {
            attemptRetryOnException("auth", request, new AuthFailureError(networkResponse));
          } else {
            // TODO: Only throw ServerError for 5xx status codes.
            throw new ServerError(networkResponse);
          }
        } else {
          throw new NetworkError(networkResponse);
        }
      }
    }
  }